4214441ac3
and skip the physical core with a system process so that programs using Intel OpenMP bind threads to cores in that manner.
70 lines
2.2 KiB
C
70 lines
2.2 KiB
C
/*
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* [x86] syscall.c
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*/
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#include <ihk/cpu.h>
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#include <ihk/debug.h>
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#include <cls.h>
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#include <syscall.h>
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//#define DEBUG_PRINT_SC
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#ifdef DEBUG_PRINT_SC
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#define dkprintf kprintf
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#else
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#define dkprintf(...)
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#endif
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/*
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See dkprintf("BSP HW ID = %d, ", bsp_hw_id); (in ./mcos/kernel/ap.c)
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Core with BSP HW ID 224 is 1st logical core of last physical core.
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It boots first and is given SW-ID of 0
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Core with BSP HW ID 0 is 1st logical core of 1st physical core.
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It boots next and is given SW-ID of 1.
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Core with BSP HW ID 1 boots next and is given SW-ID of 2.
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Core with BSP HW ID 2 boots next and is given SW-ID of 3.
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Core with BSP HW ID 3 boots next and is given SW-ID of 4.
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...
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Core with BSP HW ID 220 is 1st logical core of 56-th physical core.
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It boots next and is given SW-ID of 221.
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Core with BSP HW ID 221 boots next and is given SW-ID of 222.
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Core with BSP HW ID 222 boots next and is given SW-ID of 223.
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Core with BSP HW ID 223 boots next and is given SW-ID of 224.
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Core with BSP HW ID 225 is 2nd logical core of last physical core.
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It boots next and is given SW-ID of 225.
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Core with BSP HW ID 226 boots next and is given SW-ID of 226.
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Core with BSP HW ID 227 boots next and is given SW-ID of 227.
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*/
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static ihk_spinlock_t cpuid_head_lock = 0;
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static int cpuid_head = 1;
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/* archtecture-depended syscall handlers */
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int obtain_clone_cpuid() {
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/* see above on BSP HW ID */
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struct ihk_mc_cpu_info *cpu_info = ihk_mc_get_cpu_info();
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int cpuid, nretry = 0;
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ihk_mc_spinlock_lock_noirq(&cpuid_head_lock);
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retry:
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/* Try to obtain next physical core */
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cpuid = cpuid_head;
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cpuid_head += 4;
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if(cpuid_head >= cpu_info->ncpus) {
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cpuid_head = ((cpuid_head % 4) + 1) % 4;
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}
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/* Don't use a physical core with a system process (e.g. MPI)
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because using it degrades performance */
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if((cpu_info->ncpus - 3 <= cpuid && cpuid <= cpu_info->ncpus - 1) ||
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get_cpu_local_var(cpuid)->status != CPU_STATUS_IDLE) {
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nretry++;
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if(nretry >= cpu_info->ncpus) {
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panic("there is no cpu with empty runq\n");
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}
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goto retry;
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}
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ihk_mc_spinlock_unlock_noirq(&cpuid_head_lock);
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return cpuid;
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}
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